(a) Field of the Invention
The present invention relates to a method for precisely detecting the deviation from a lane by a vehicle.
(b) Description of the Related Art
Vehicles are driven in a lane between lane markers. However, drivers may sometimes inadvertently drive vehicles out of the lane as a result of a distraction, carelessness, fatigue, etc. A potentially dangerous situation results if the driver does not quickly correct his or her error. Accordingly, there have been proposed methods and systems that detect the deviation from a lane by a vehicle, then alert the driver by the sounding of an alarm or by providing a visual warning.
Such systems and methods perform the task of determining lane deviations by ascertaining the width of the lane and the position of the vehicle with respect to the lane markers. Many processes are involved in this process. The initial step is to detect the left and right lane markers in front of the vehicle. Calculations are then performed using the detected left and right lane markers by utilizing predetermined values established in a memory table. The width of the lane is determined by these calculations. Next, a longitudinal center line between the detected lane markers corresponding to a halfway point between the lane markers is determined and a position of a longitudinal center line of the vehicle, which is established in the memory table and varies according to vehicle type, is detected. Finally, the center lines are compared and lane drifting is determined to be occurring if the center lines do not correspond within a predetermined range. If the vehicle is determined to be deviating from the lane, the driver is alerted.
In conventional systems and methods as described above, however, the erroneous detection of lane deviation may occur when there are curves in the road and also when changing lanes such that the driver is unnecessarily alerted.